Improvement in saw-gummerj



DAVID HUFFMAN, 0F LURAY, VIRGINIA.

Letters Patent No. 112,711, dated March 14, 1871."

IMP'ROVEMENT IN SAW-GUMMEH.

The Schedule referred to in these Letters Patent and making part of thesame.

To all whom it may concern:

Bc it known` that I, DAVID HUFFMAN, of Luray, in the county of Page andState of Virginia, have invented a new and improved Machine forItetoothing or Gumming Circular or other Mill-Saws; and I do herebydeclare that the following is a full, clear, and exact description ofthe same, reference being had to the accompanying drawing making a partof this speciication.

Nature and Object of thc Intention.

The invention consists of devices, too fully describen hereafter' toneed preliminary explanation, whereby the curved backs and throats ofsaw-teeth may be regularly and speedily formed or re-cut.

Descrzptwn of the Accompanying l'mwiag' Figure l is a side view of myimproved machine for sharpening or gumniing circular saws;

Figure 2, a plan view of the same; and hhigures 3 and 4, detached viewsi' parts of the mao me.

General Description.

vthe lower portion of the frame, so as to suit saws ot' d'erentdiameters, and the upper portion of the said s aw extends through anarrow slot, a', formed for its reception in the portions A and A of theframe.

-In order to prevent the saw from turning when being operated upon bythe machine, as hereafter explained, it is tirmly held by a visearranged lwithin the portion A' of the frame, ou either side of the slotai,

- in such a manner that its jaws a a can be forced together byhorizontall screws.

The vise arranged to clamp the saw, as above described, is similar tothat described in my patent of October 27, 1868, for a device forsharpening saws.

The cutti1'1g-tool o1' gummer b is attached to a short spindle,f1), hungtransversely to a forked arm, B, the branches b" lr of which extend one" ther side oi' the saw, and are pivoted by the driving-slvlaft to theportion A of the frame, at such points that the cutter, when the saidarms are turned upon their pivot, may be caused to travel in the arc'ofacircle eccentric to the center of the saw, or, in other words, in acurve corresponding to thatol" the backsl of the teeth ofthe said saw.In order that the length of the radius of the curve described bythecutter may be varied to suit the dilerent sizes of saw-teeth to 'beoperated upon, I

the arm B is provided, near the extremities ofits forked ends, with anumber of holes, through any ot which the pivoting-shaft 0r pins may bepassed.

The arm B is supported, near its outer end, by a screw-rod, c, whichpasses through and is adapted to the 'threads of a split nut, c,attached to arms c c on the 'rame of the machine, as willl be more,fully described hereafter; and at the upper end of the said screw-'rodthere is a bevel-wheel,D, gearing into a smallerl wheel, d, of ahorizontal spindle, d', which is hung to the arm B, and is alsoprovided'with a bandwheel, E, through the medium oifwhich and a belt orcord it receives its motion from a small pulley at one end of thecutter-spindle b'.

rlhe latter has, at its `opposite end, a large cogwheel, F, which isdriven, through the medium of a series of small gear-wheels, c, by adriving-pulley, F', the center of which coincides with that of the-pivot of the arm B, or with that of the driving-shait w, to which thepulley F is attached.

It will be seen that, when the point on which the arm B' swings ischanged, one, or more, ofthe pinions e is removed, or additional pinionsare inserted, so as to maintain the connection between the drivin`gshaftand the cutter-shaft.

It will be evident that whenthe cutter b is rotated bythe abovearrangement of gearing, it will also be i @used to descend graduallywith the arm B, owing to the motion imparted to the screw-rod c and theconsequent descent of the latter through the nut cf The nut c consistsof a cross-piece extending bctweeu the arms or extensions c of the frameof the machine, and having at each end trunnions fitted to and arrangedto turn in the said extensions, in orderthat it may -adaptitself to thevarious angles assumed. by the'screw-rod, as the latter descends withthe arm. The said nut is also split or formed in two sections,

detachable from each other, so that the screw-rod,A

when completely lowered, may be quickly raised with the arm B, withoutreversing its motion and causing it to travel slowly upward through thenut. When the screw-rod is descending .the two sections of the split nutare held firmly together by bands or rings c', which may be slippedlongitudinally toward the trunnions when the sections are to beseparated.

The nut is introduced into its place between the arms c through auopening in one of the latter, which is afterward'filled with a bushing,t', adapted to receive one of the trunnions of the nut, (see iig. 3.)

In order that the cutter' b may he worn away regularly, instead of atthe center only, it isvarranged to have a longitudinal movement upon itsspindle as it is rotated. This motion is imparted it by a lever, hi,

hung to the arm B at the point h, and embracing, A'with one of itsforked ends, a cam, h, on the screwrod, c, while its `opposite forkedend, h3, extends ou either side of the cutter.

Operation.

The saw, the teeth of which are to be gummed or re-cut, is attached tothe frame of the machine, as before described, and the' arm B, carryingthe cutter, is pivoted. to the frame in such a position that the ncuttermay be caused to travel in the arc of a circle corresponding to 'theproper curve of the backs of the teeth of the saw. Y y

The machine having been thus adjusted, the saw is rigidly securedbetween the jaws a a ot' the vise, to' prevent it from turning, and thearm B is raised until the cutter bears against the back of the tooth tobe operated upon at the point of the same. The machine is then set inmotion, andthe cutter begins to operate upon the back of the tooth, itbeing at the same time carried gradually downward by the actionof thescrew c, until it has entered and re-cntthe throat of the succeedingtooth. j

The machine is then stopped, and the sections of 1the split nut c areseparated, so as to permit the screwrod, together with the arm B and itscutter, to be raised .to their former positions, after'whichthe'pressure of the vise upon the saw is relieved,and the saw is turnedto a sufiicient extent to permit the next tooth to be -broughtto theposition previously occupied by the tooth which has been ont. The saw isthen secured between the jaws of the vise as before, and theabovedescribedoperations are repeated, the remaining teeth beingsuccessively operated upon in like manner.

TheV above machine, although intended mainly for :operating upon theteeth of circular saws, can, withl out material alteration, be adaptedfor mill-saws which have teeth with curved backs.

The machine can be considerably -modied without departing from the mainfeatures -of myinvention. For instance, the arrangement of the gearingand of the devices for raising,r and lowering the pivoted arm and cuttermight bedilerent from that described, or the frame-of the machine mightbe diii'erently constructed, or be altogether dispensed with asa supportfor the saw, where the lattereould be operated upon without removing itfrom its bearings. In this latter case the arm carrying the cutter mightbe pivoted to the saw itself, or to any attachment thereto, providingonly that the said arm be pivoted eccentrically in respect to the centerof the saw.

It will be seen that, by suspending the saw in a frame, A, the necessityof removing and readjusting the apparatus after cutting each tooth isavoided, the saw being turned on the mandrel or shaft after each toothis cnt, so as to bring the next into position, where it is held by thevise. saw the further and more important result of operating the cutterby power, instead of by hand, as heretofore, is effected, for as theframe is stationary, its drivingshaft can be driven, as described, fromany adjacent cutting apparatus must be adjusted on the saw afteroperating on each tooth.

Claims.

1. The combination of the frame A, its adjustable mandrel on which tosuspend a` circular saw, and the arm B, carrying a rotating cutter in acurved path eccentric to the center ofthe saw, said cutter being drivenfrom a shaft, the axis of which coincides with the fnl# crnm of 4saidarm B.

2. The combination of the frame carrying the arm B and its rotatingcutter, and the split nut c and screwshaft C connected to the arm B, andoperated through the medium of devices substantially as described.

3. The arm B carrying the cutter, and having its pivot coinciding withthe axis of the drivingfshaft', and provided with detachable pulleys, eor equivalent devices, lwhereb'y the arm may be adj usted withoutinterfering with the operation ofthe cutter, substantially as described.

ited lateral movement, and the forked lever h and cam j, or theirequivalent.

To the above specification of my invention I have signed my hand this21st day of January, 187i);

DAVID HU'FFMAN;

Witnesses:

GEO. E. BRowN, .Otras-'A1 Pmrrr.

By thus suspending the` shafting--a result which lcannot be obtainedwhen the 4. Thecombination of the cutter, capable of a 1im-.

